EP0219466A2 - Dispositif pour indiquer le passage d'un intrus à travers la ligne de démarcation d'une région déterminée - Google Patents

Dispositif pour indiquer le passage d'un intrus à travers la ligne de démarcation d'une région déterminée Download PDF

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Publication number
EP0219466A2
EP0219466A2 EP86830277A EP86830277A EP0219466A2 EP 0219466 A2 EP0219466 A2 EP 0219466A2 EP 86830277 A EP86830277 A EP 86830277A EP 86830277 A EP86830277 A EP 86830277A EP 0219466 A2 EP0219466 A2 EP 0219466A2
Authority
EP
European Patent Office
Prior art keywords
tubes
transducer
bypass duct
liquid
boundary
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP86830277A
Other languages
German (de)
English (en)
Other versions
EP0219466A3 (fr
Inventor
Luigi Bianco
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Elkron SpA
Original Assignee
Elkron SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Elkron SpA filed Critical Elkron SpA
Publication of EP0219466A2 publication Critical patent/EP0219466A2/fr
Publication of EP0219466A3 publication Critical patent/EP0219466A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/20—Actuation by change of fluid pressure

Definitions

  • the present invention relates to alarm apparatus for signalling the passage of an intruder across the boundary of a predetermined region.
  • the invention relates to apparatus of the type including at least one pair of yieldable tubes which are intended to be filled with fluid and buried along the boundary of the region and which can transmit an energy pulse in response to pressure applied to the exterior of a tube, and transducer means for converting the energy pulse into an alarm signal.
  • Apparatus of the aforesaid type is. known from US patent No. 3,438,021, in which each tube is yieldable and is connected at one end to a respective diaphragm-type transducer device.
  • This apparatus has the disadvantage of requiring accurate electrical balancing between the respective transducer devices and this is particularly difficult in view of the extreme sensitivity of the transducer devices themselves which may be influenced by variations of temperature and of the nature of the ground in which the apparatus is buried, and variations in the resistance of the materials, for example, as a result of ageing.
  • the object of the present invention is to provide an improved apparatus which is highly reliable and provides a constant response signal over the working life of the apparatus, and which requires minimum maintenance.
  • Figure 1 illustrates diagrammatically apparatus according to the invention intended to be buried along the boundary of a predetermined region to detect the passage of an intruder across this boundary.
  • the apparatus comprises a pair of yieldable tubes 2 and 4 which are intended to be filled with pressurised liquid L and buried at a typical depth of about 40-60cms, substantially parallel to each other and about 1-1.5m apart.
  • the tubes 2 and 4 are made of a yieldable material, such as rubber, and the liquid is typically water with possible additives for lowering its freezing point.
  • the two yieldable tubes are connected at one end to a pressure transducer device 8 of the two-directional differential type, including diaphragm means, indicated 16, and pressure sensor means 42 ( Figure 3), which will be described in more detail below and which can output an electrical signal in response to a variation between the pressures in the two tubes.
  • a processing circuit 12 is associated with the transducer and is arranged to output an electrical signal which is converted into an alarm signal by an alarm device 14 when the signal output by the transducer exceeds a predetermined threshold.
  • a bypass duct 18 is connected at its ends to the transducer device on opposite sides of the diaphragm means 16.
  • the bypass duct includes two branches 20a and 20b which are hydraulically connected in parallel and in which are mounted two one-way on-off valves 22 that are hydraulically in antiparallel to each other. These valves 22 are arranged to put the two tubes 2 and 4 suddenly into liquid communication when the difference between the pressures in the two tubes exceeds a predetermined threshold.
  • Capillary means 24 are interposed in the bypass duct, preferably hydraulically in parallel with each valve 22.
  • a pressure switch device 25 is connected to at least one of the two tubes, or is in liquid communication with therewith-, for providing an alarm signal when the pressure in the tube with which it is associated falls below a threshold.
  • a duct for supplying liquid from a source 30 is indicated 26; the duct 26 communicates by means of two branches 26a and 26b with the bypass duct 18.
  • a differential valve 28 is connected in the supply duct and can enable the supply of pressurised liquid to the tubes 2 and 4 should the pressure in the two tubes fall below an operative value for the apparatus.
  • each tube 2 and 4 are not interconnected and are each provided with a respective vent valve 32 for venting air from.the two tubes during the refilling of the tubes with pressurised liquid supplied through the duct 26.
  • FIG. 2 illustrates a housing 10 made, for example, by die-casting and constituted by a number of sectional parts.
  • the housing 10 defines an internal chamber 34 communicating through respective ducts 36, 38 and connector members 40 with the two tubes 2 and 4.
  • the transducer device 8 is mounted in the chamber 34 between the two connectors 36, 38.
  • the transducer 8 includes first and second diaphragms 16a, 16b fixed to the walls of the chamber 3 4 with a liquid-tight seal.
  • Each diaphragm is operatively associated with a respective pressure sensor 42, preferably of piezoelectric type.
  • the two diaphragms 16a and 16b are mounted with their respective opposing sensors preferably facing each other and are connected together by the interposition of a waterproof glue 44.
  • the surface of each diaphragm facing the liquid may optionally be covered with a layer of waterproofing material.
  • FIG. 4 illustrates in detail a one-way flow valve 22 connected in the bypass duct 18.
  • Each valve 22 has a tubular body 46 inserted in a chamber 48 defined by the housing 10 and communicating with the respective branch 20a or 20b of the bypass duct through apertures 50 and 52.
  • the tubular body 46 defines an axial duct 47 with an inlet opening 49 and has an internally-threaded end 56 mounted in the body 10 and another internally-threaded end 60.
  • the tubular body 46 has a radial capillary duct 64 which constitutes the capillary communication means which enable the pressure in the two tubes to balance slowly.
  • the tubular body 46 has two or more radial ducts 62 adjacent to a surface 66 which acts as a valve seat and cooperates with a spherical obturator member 68 which is held in a closed position under the action of resilient means 70 inserted in the tubular body 46 and interacting axially between the obturator and an internally-hexagonal screw 62 inserted in the end 60.
  • a sudden pressure drop in one of the tubes 2 and 4 causes the one-way flow valve to open, allowing rapid passage of liquid through the bypass duct to equalise the pressure in the two tubes again. This sharp pressure drop may be caused, for example, by failure of the material or damage to the tubes caused, for example by a rodent.
  • the pressure in the tubes is balanced immediately and damage to the transducer device is thus avoided.
  • the capillary means constituted by the duct 64 enable slow balancing of the pressures in the two tubes while allowing a pressure difference to be established between the two tubes in transitory conditions in order to activate the alarm signal.
  • the apparatus includes a test device (not illustrated) for indicating that the transducer is operational.
  • This test device is preferably constituted by means for supplying one or other of the sensors independently with an electrical signal which can cause the deformation of the sensor and the diaphragm associated therewith. The deformation of the diaphragm in its turn causes the deformation of the other diaphragm rigidly connected thereto and of the respective sensor, causing a response signal which is processed by the processing circuit 12.
  • This test system allows the functioning of the transducer to be checked extremely simply.
  • the processing circuit 12 and its alarm device are preferably located within the housing 10.
  • the processing circuit 12 may conveniently be arranged to differentiate the direction in which the intruder crosses the boundary of the region defined by the yieldable tubes on the basis of the signal provided by the transducer.
  • the alarm device 14 is provided with separate optical or audible signalling devices which are activated by the processing circuit to signal whether the crossing or approach to the boundary has occurred in one direction or the other, or to provide an indication of the type of intrusion occurring.
  • the housing 10 has a plurality of pairs of connectors of the type indicated 40 with respective pairs of ducts communicating with the chamber 34 on opposite sides of the transducer.
  • These auxiliary connector members enable a plurality of pairs of yieldable tubes to be connected to the transducer to extend the range of detection of the apparatus itself.
  • the connectors are arranged to receive respective obturators when the supplementary pairs of yieldable tubes are not used.

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  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)
EP86830277A 1985-10-04 1986-10-01 Dispositif pour indiquer le passage d'un intrus à travers la ligne de démarcation d'une région déterminée Withdrawn EP0219466A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT6784385 1985-10-04
IT67843/85A IT1182588B (it) 1985-10-04 1985-10-04 Apparecchiatura perfezionata per segnalare il passaggio di un intruso attraverso il confine di una regione predeterminata

Publications (2)

Publication Number Publication Date
EP0219466A2 true EP0219466A2 (fr) 1987-04-22
EP0219466A3 EP0219466A3 (fr) 1988-11-23

Family

ID=11305729

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86830277A Withdrawn EP0219466A3 (fr) 1985-10-04 1986-10-01 Dispositif pour indiquer le passage d'un intrus à travers la ligne de démarcation d'une région déterminée

Country Status (2)

Country Link
EP (1) EP0219466A3 (fr)
IT (1) IT1182588B (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108332885A (zh) * 2018-03-06 2018-07-27 中国航发哈尔滨东安发动机有限公司 一种力的监测结构

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2029062A (en) * 1978-08-24 1980-03-12 Italcontrol Srl Intruder detection

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2029062A (en) * 1978-08-24 1980-03-12 Italcontrol Srl Intruder detection

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108332885A (zh) * 2018-03-06 2018-07-27 中国航发哈尔滨东安发动机有限公司 一种力的监测结构

Also Published As

Publication number Publication date
EP0219466A3 (fr) 1988-11-23
IT8567843A0 (it) 1985-10-04
IT1182588B (it) 1987-10-05

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Inventor name: BIANCO, LUIGI